Oligosaccharides from Vitis vinifera grape seeds: a focus on gentianose as a novel bioactive compound

One of the consequences of global warming is the quick berry development giving rise to a disconnection between sugar accumulation and the formation of important quality minor compounds such as phenolics and volatile compounds being a huge challenge for the oenologist [1]. Thus, this phenomenon is forcing the search on strategies for maintaining the quality of wines despite this situation. One possibility is to make an early harvest with a low sugar concentration (18ºbrix) and advanced harvest for sparkling wine (20-21ºbrix) and afterwards to combine base wines properly and carry out the second fermentation trying to compensate the lack of secondary metabolites due to the quick berry development and higher alcohol degree of the second one, not adequate itself for sparkling wine. The aim of this study was to assess the chemical and physical characteristics, mainly volatile profile, and foaming properties of sparkling wines from grapes of Chardonnay and Sauvignon blanc.

Grafting plants uses intrinsic healing processes to join two different plants together to create one functional organism. To further our understanding of the molecular changes occurring during graft union formation in grapevine, we characterized the metabolome and transcriptome of intact and wounded cuttings (with and without buds to represent scions and rootstocks respectively), and homo- and heterografts at 0 and 14 days after wounding/grafting. As over-wintering, dormant plant material was grafted, we also characterized the gene expression changes in the wood during bud burst and spring activation of growth. We observed an asymmetrical pattern of gene expression between above and below the graft interface, auxin and sugar related genes were up-regulated above the graft interface, while genes involved in stress responses were up-regulated below the graft interface.

Nitrogen (N) supply strongly influences vine productivity and berry composition, matching availability and uptake requirements of vines during the growing season is essential to optimize vine nutrition. The nutritional status of grapevines is commonly assessed by the determination of petiole nutrient concentrations at flowering. The reserve N could also be an earlier indicator for grapevine N status, this work aimed to assess how the petiole levels relate to these perennial N reserves.

Grapevine downy mildew (GDM), caused by the obligate biotroph oomycete Plasmopara viticola, is one of the most destructive diseases in viticulture.

Light-induced reactions can be responsible for detrimental changes of white and rosé wines. This is associated to the photo-degradation of riboflavin (RF) and of methionine (Met) causing the appearance of light-struck taste (LST).